A GPS-denied drone landing simulation using relative sensors (IMU, altimeter, camera, landing pad detection) with PyBullet and Gazebo simulators.

Quick Start

# Install (Ubuntu)
./setup/install_ubuntu.sh
source activate.sh

# Run PyBullet simulation
python simulation_host.py      # Terminal 1: Simulator
python ros_bridge.py           # Terminal 2: ROS bridge
python controllers.py          # Terminal 3: Drone + Rover controllers

# With moving rover
python controllers.py --pattern circular --speed 0.3

Architecture

┌─────────────────────────────────────────────────────────────────────────┐
│  ┌──────────────────┐                    ┌──────────────────────────┐   │
│  │ simulation_host  │◄── UDP:5555 ──────►│    ros_bridge.py         │   │
│  │   (PyBullet)     │                    └────────────┬─────────────┘   │
│  └──────────────────┘                                 │                 │
│          OR                                           │                 │
│  ┌──────────────────┐                    ┌────────────┴─────────────┐   │
│  │     Gazebo       │◄── ROS Topics ────►│    gazebo_bridge.py      │   │
│  └──────────────────┘                    └────────────┬─────────────┘   │
│                                                       │                 │
│                                          ┌────────────▼─────────────┐   │
│                                          │    controllers.py        │   │
│                                          │  ┌─────────────────────┐ │   │
│                                          │  │  DroneController    │ │   │
│                                          │  │  RoverController    │ │   │
│                                          │  └─────────────────────┘ │   │
│                                          └──────────────────────────┘   │
└─────────────────────────────────────────────────────────────────────────┘

Files

File	Description
`simulation_host.py`	PyBullet physics simulator
`ros_bridge.py`	UDP ↔ ROS 2 bridge
`gazebo_bridge.py`	Gazebo ↔ ROS 2 bridge
`controllers.py`	Runs drone + rover together
`drone_controller.py`	Drone landing logic (edit this)
`rover_controller.py`	Moving landing pad

Controller Options

python controllers.py --help

Options:
  --pattern, -p   Rover pattern: stationary, linear, circular, random, square
  --speed, -s     Rover speed in m/s (default: 0.5)
  --amplitude, -a Rover amplitude in meters (default: 2.0)

GPS-Denied Sensors

The drone has no GPS. Available sensors:

Sensor	Data
IMU	Orientation, angular velocity
Altimeter	Altitude, vertical velocity
Velocity	Estimated horizontal velocity
Camera	320x240 downward-facing image (base64 JPEG)
Landing Pad	Relative position when visible (may be null)

Documentation

Document	Description
Installation	Setup for Ubuntu, macOS, Windows
Architecture	System components and data flow
Protocol	Sensor data formats
Drone Guide	How to implement landing logic
Rover Controller	Movement patterns
PyBullet	PyBullet-specific setup
Gazebo	Gazebo-specific setup

Getting Started

Read docs/drone_guide.md
Edit drone_controller.py
Implement calculate_landing_maneuver()
Run: python controllers.py --pattern stationary
Increase difficulty: python controllers.py --pattern circular